plugeth/swarm/api/client/client.go

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// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
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// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
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// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
//
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// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package client
import (
"archive/tar"
"bytes"
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"mime"
"mime/multipart"
"net/http"
"net/textproto"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/ethereum/go-ethereum/swarm/api"
)
var (
DefaultGateway = "http://localhost:8500"
DefaultClient = NewClient(DefaultGateway)
)
func NewClient(gateway string) *Client {
return &Client{
Gateway: gateway,
}
}
// Client wraps interaction with a swarm HTTP gateway.
type Client struct {
Gateway string
}
// UploadRaw uploads raw data to swarm and returns the resulting hash
func (c *Client) UploadRaw(r io.Reader, size int64) (string, error) {
if size <= 0 {
return "", errors.New("data size must be greater than zero")
}
req, err := http.NewRequest("POST", c.Gateway+"/bzzr:/", r)
if err != nil {
return "", err
}
req.ContentLength = size
res, err := http.DefaultClient.Do(req)
if err != nil {
return "", err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return "", fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
data, err := ioutil.ReadAll(res.Body)
if err != nil {
return "", err
}
return string(data), nil
}
// DownloadRaw downloads raw data from swarm
func (c *Client) DownloadRaw(hash string) (io.ReadCloser, error) {
uri := c.Gateway + "/bzzr:/" + hash
res, err := http.DefaultClient.Get(uri)
if err != nil {
return nil, err
}
if res.StatusCode != http.StatusOK {
res.Body.Close()
return nil, fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
return res.Body, nil
}
// File represents a file in a swarm manifest and is used for uploading and
// downloading content to and from swarm
type File struct {
io.ReadCloser
api.ManifestEntry
}
// Open opens a local file which can then be passed to client.Upload to upload
// it to swarm
func Open(path string) (*File, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
stat, err := f.Stat()
if err != nil {
f.Close()
return nil, err
}
return &File{
ReadCloser: f,
ManifestEntry: api.ManifestEntry{
ContentType: mime.TypeByExtension(filepath.Ext(path)),
Mode: int64(stat.Mode()),
Size: stat.Size(),
ModTime: stat.ModTime(),
},
}, nil
}
// Upload uploads a file to swarm and either adds it to an existing manifest
// (if the manifest argument is non-empty) or creates a new manifest containing
// the file, returning the resulting manifest hash (the file will then be
// available at bzz:/<hash>/<path>)
func (c *Client) Upload(file *File, manifest string) (string, error) {
if file.Size <= 0 {
return "", errors.New("file size must be greater than zero")
}
return c.TarUpload(manifest, &FileUploader{file})
}
// Download downloads a file with the given path from the swarm manifest with
// the given hash (i.e. it gets bzz:/<hash>/<path>)
func (c *Client) Download(hash, path string) (*File, error) {
uri := c.Gateway + "/bzz:/" + hash + "/" + path
res, err := http.DefaultClient.Get(uri)
if err != nil {
return nil, err
}
if res.StatusCode != http.StatusOK {
res.Body.Close()
return nil, fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
return &File{
ReadCloser: res.Body,
ManifestEntry: api.ManifestEntry{
ContentType: res.Header.Get("Content-Type"),
Size: res.ContentLength,
},
}, nil
}
// UploadDirectory uploads a directory tree to swarm and either adds the files
// to an existing manifest (if the manifest argument is non-empty) or creates a
// new manifest, returning the resulting manifest hash (files from the
// directory will then be available at bzz:/<hash>/path/to/file), with
// the file specified in defaultPath being uploaded to the root of the manifest
// (i.e. bzz:/<hash>/)
func (c *Client) UploadDirectory(dir, defaultPath, manifest string) (string, error) {
stat, err := os.Stat(dir)
if err != nil {
return "", err
} else if !stat.IsDir() {
return "", fmt.Errorf("not a directory: %s", dir)
}
return c.TarUpload(manifest, &DirectoryUploader{dir, defaultPath})
}
// DownloadDirectory downloads the files contained in a swarm manifest under
// the given path into a local directory (existing files will be overwritten)
func (c *Client) DownloadDirectory(hash, path, destDir string) error {
stat, err := os.Stat(destDir)
if err != nil {
return err
} else if !stat.IsDir() {
return fmt.Errorf("not a directory: %s", destDir)
}
uri := c.Gateway + "/bzz:/" + hash + "/" + path
req, err := http.NewRequest("GET", uri, nil)
if err != nil {
return err
}
req.Header.Set("Accept", "application/x-tar")
res, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
tr := tar.NewReader(res.Body)
for {
hdr, err := tr.Next()
if err == io.EOF {
return nil
} else if err != nil {
return err
}
// ignore the default path file
if hdr.Name == "" {
continue
}
dstPath := filepath.Join(destDir, filepath.Clean(strings.TrimPrefix(hdr.Name, path)))
if err := os.MkdirAll(filepath.Dir(dstPath), 0755); err != nil {
return err
}
var mode os.FileMode = 0644
if hdr.Mode > 0 {
mode = os.FileMode(hdr.Mode)
}
dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, mode)
if err != nil {
return err
}
n, err := io.Copy(dst, tr)
dst.Close()
if err != nil {
return err
} else if n != hdr.Size {
return fmt.Errorf("expected %s to be %d bytes but got %d", hdr.Name, hdr.Size, n)
}
}
}
// UploadManifest uploads the given manifest to swarm
func (c *Client) UploadManifest(m *api.Manifest) (string, error) {
data, err := json.Marshal(m)
if err != nil {
return "", err
}
return c.UploadRaw(bytes.NewReader(data), int64(len(data)))
}
// DownloadManifest downloads a swarm manifest
func (c *Client) DownloadManifest(hash string) (*api.Manifest, error) {
res, err := c.DownloadRaw(hash)
if err != nil {
return nil, err
}
defer res.Close()
var manifest api.Manifest
if err := json.NewDecoder(res).Decode(&manifest); err != nil {
return nil, err
}
return &manifest, nil
}
// List list files in a swarm manifest which have the given prefix, grouping
// common prefixes using "/" as a delimiter.
//
// For example, if the manifest represents the following directory structure:
//
// file1.txt
// file2.txt
// dir1/file3.txt
// dir1/dir2/file4.txt
//
// Then:
//
// - a prefix of "" would return [dir1/, file1.txt, file2.txt]
// - a prefix of "file" would return [file1.txt, file2.txt]
// - a prefix of "dir1/" would return [dir1/dir2/, dir1/file3.txt]
//
// where entries ending with "/" are common prefixes.
func (c *Client) List(hash, prefix string) (*api.ManifestList, error) {
res, err := http.DefaultClient.Get(c.Gateway + "/bzz:/" + hash + "/" + prefix + "?list=true")
if err != nil {
return nil, err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return nil, fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
var list api.ManifestList
if err := json.NewDecoder(res.Body).Decode(&list); err != nil {
return nil, err
}
return &list, nil
}
// Uploader uploads files to swarm using a provided UploadFn
type Uploader interface {
Upload(UploadFn) error
}
type UploaderFunc func(UploadFn) error
func (u UploaderFunc) Upload(upload UploadFn) error {
return u(upload)
}
// DirectoryUploader uploads all files in a directory, optionally uploading
// a file to the default path
type DirectoryUploader struct {
Dir string
DefaultPath string
}
// Upload performs the upload of the directory and default path
func (d *DirectoryUploader) Upload(upload UploadFn) error {
if d.DefaultPath != "" {
file, err := Open(d.DefaultPath)
if err != nil {
return err
}
if err := upload(file); err != nil {
return err
}
}
return filepath.Walk(d.Dir, func(path string, f os.FileInfo, err error) error {
if err != nil {
return err
}
if f.IsDir() {
return nil
}
file, err := Open(path)
if err != nil {
return err
}
relPath, err := filepath.Rel(d.Dir, path)
if err != nil {
return err
}
file.Path = filepath.ToSlash(relPath)
return upload(file)
})
}
// FileUploader uploads a single file
type FileUploader struct {
File *File
}
// Upload performs the upload of the file
func (f *FileUploader) Upload(upload UploadFn) error {
return upload(f.File)
}
// UploadFn is the type of function passed to an Uploader to perform the upload
// of a single file (for example, a directory uploader would call a provided
// UploadFn for each file in the directory tree)
type UploadFn func(file *File) error
// TarUpload uses the given Uploader to upload files to swarm as a tar stream,
// returning the resulting manifest hash
func (c *Client) TarUpload(hash string, uploader Uploader) (string, error) {
reqR, reqW := io.Pipe()
defer reqR.Close()
req, err := http.NewRequest("POST", c.Gateway+"/bzz:/"+hash, reqR)
if err != nil {
return "", err
}
req.Header.Set("Content-Type", "application/x-tar")
// use 'Expect: 100-continue' so we don't send the request body if
// the server refuses the request
req.Header.Set("Expect", "100-continue")
tw := tar.NewWriter(reqW)
// define an UploadFn which adds files to the tar stream
uploadFn := func(file *File) error {
hdr := &tar.Header{
Name: file.Path,
Mode: file.Mode,
Size: file.Size,
ModTime: file.ModTime,
Xattrs: map[string]string{
"user.swarm.content-type": file.ContentType,
},
}
if err := tw.WriteHeader(hdr); err != nil {
return err
}
_, err = io.Copy(tw, file)
return err
}
// run the upload in a goroutine so we can send the request headers and
// wait for a '100 Continue' response before sending the tar stream
go func() {
err := uploader.Upload(uploadFn)
if err == nil {
err = tw.Close()
}
reqW.CloseWithError(err)
}()
res, err := http.DefaultClient.Do(req)
if err != nil {
return "", err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return "", fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
data, err := ioutil.ReadAll(res.Body)
if err != nil {
return "", err
}
return string(data), nil
}
// MultipartUpload uses the given Uploader to upload files to swarm as a
// multipart form, returning the resulting manifest hash
func (c *Client) MultipartUpload(hash string, uploader Uploader) (string, error) {
reqR, reqW := io.Pipe()
defer reqR.Close()
req, err := http.NewRequest("POST", c.Gateway+"/bzz:/"+hash, reqR)
if err != nil {
return "", err
}
// use 'Expect: 100-continue' so we don't send the request body if
// the server refuses the request
req.Header.Set("Expect", "100-continue")
mw := multipart.NewWriter(reqW)
req.Header.Set("Content-Type", fmt.Sprintf("multipart/form-data; boundary=%q", mw.Boundary()))
// define an UploadFn which adds files to the multipart form
uploadFn := func(file *File) error {
hdr := make(textproto.MIMEHeader)
hdr.Set("Content-Disposition", fmt.Sprintf("form-data; name=%q", file.Path))
hdr.Set("Content-Type", file.ContentType)
hdr.Set("Content-Length", strconv.FormatInt(file.Size, 10))
w, err := mw.CreatePart(hdr)
if err != nil {
return err
}
_, err = io.Copy(w, file)
return err
}
// run the upload in a goroutine so we can send the request headers and
// wait for a '100 Continue' response before sending the multipart form
go func() {
err := uploader.Upload(uploadFn)
if err == nil {
err = mw.Close()
}
reqW.CloseWithError(err)
}()
res, err := http.DefaultClient.Do(req)
if err != nil {
return "", err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return "", fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
data, err := ioutil.ReadAll(res.Body)
if err != nil {
return "", err
}
return string(data), nil
}